
LXE1710 E
VALUATION
B
OARD
C
APACITOR
S
ELECTION
The LC filter design section discusses filter options
and the calculation of component values. However,
the specification of capacitor type depends on the
application in the circuit. The table provides
descriptions and guidelines for capacitors in the
AudioMAX amplifier board.
U
SER
G
UIDE
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 13
Copyright
2000
Rev. 1.1, 2000-12-01
Reference
Designator
Capacitor
Comments
C10, C11
FET gate drive
These
! "#! $! $ "! % #! &'!
C3 C14
Audio input path
These decoupling capacitors are used for the audio input +/- signals.
C18, C19,
C20, C21
Output filter
The output filter metal film capacitors (low ESR, 5% tolerance) work well to set an accurate
corner frequency at a low cost.
These metal film capacitors are used for the power supply bypass for the FETs. Place
adjacent to the FETs or consider lower value ESR solutions depending on the PCB
component placement.
C8, C12
FET bypass
C22
LX1710 bypass
The metal film capacitor is a high frequency bypass for the LX1710 IC.
C9, C13
VDD,
PVDD bypass
These tantalum capacitors provide the bypass for the IC supply voltage and output driver
supply voltage utilizing a minimal footprint area.
C17
Output power stage
The electrolytic filter capacitor smoothes out ripple current and should be placed close to the
output FETs.
C16
Oscillator frequency
The timing capacitor (5% tolerance) sets the oscillator frequency.
C6, C7
Feedback filter
These (5%) capacitors are used in the RC filter to provide feedback for the control loop.
C4, C5
Error amplifier
These (5%) capacitors create the compensation network. Make sure the appropriate
“temperature grade” is used to ensure stability.
C1, C2
Voltage references
The filter capacitors provide the bypass for the 5V and 2.5V references.
C26
Audio input filter
The RC filter minimizes high frequency noise to the amplifier.
Capacitor Description